The proposed research is designed to determine the relationship between amalgam alloy formulation, creep and other mechanical properties, corrosion resistance, microstructure of Cu rich amalgams, and in vivo performance. Saline and sulfide corrosion resistance of new and experimental amalgams will be evaluated as well as steady state creep parameters and axial tensile stress-strain relationships. Alteration of microstructure resulting from these investigations will be determined by scanning electron microscopy and energy dispersive x-ray analysis (qualitative and quantitative analysis of compositional variations). Synergistic effects of corrosion, creep, and alloying modifications will be investigated via corrosion-creep testing and systematic alloying variations to produce distinctive amalgams with potential for superior clinical performance. In vivo studies in dogs of various amalgams possessing widely varying creep and corrosion tendencies will be conducted to establish cause-effect relationships between clinical performance and the in vitro test parameters.